VOCs play an increasingly important role in affecting air quality and threatening human health in China in recent years,where industry activities show a significant contribution to VOCs emission.In this article we rep...VOCs play an increasingly important role in affecting air quality and threatening human health in China in recent years,where industry activities show a significant contribution to VOCs emission.In this article we report our long term study of industrial VOCs emissions of six major industries (vehicle manufacturing,printing,equipment coating,electronic manufacturing,furniture manufacturing and bio-pharming) on the aspects of emission characteristics,environmental impact and health risk assessment,and control challenge analysis with the purpose to obtain in-depth understanding of industry VOCs emissions and offer some original basements for national control and management of industry VOCs emissions.This study shows that all these industries give middle or low emission with total VOCs concentration less than 1000 mg/m3 at each exhaust pipe.Benzenes,esters,alcohols,ketones,alkanes,chloroalkanes and alkenes were detected as the major emission components and the most frequently monitored VOCs were benzenes,which varied obviously with different processes and industries.The environmental impact assessments indicate that vehicle manufacturing and benzenes should be prior controlled with the purpose to reduce air pollution.While,health risk assessments suggest that furniture manufacturing and chloroalkanes should be firstly controlled.Control analysis indicates that developing technologies with low cost and high efficiency and establishing and completing specific industry emission standards/regulations are the two key issues in VOCs emission management at present stage.展开更多
利用声发射无损探伤技术实时监测三种类型超高性能混凝土(Ultra High Performance Concrete,简称UHPC)轴拉试验过程中内部损伤点的形成和演化过程,同时通过裂缝观测仪量测UHPC拉应变到达2000με时的缝宽。与低应变强化UHPC和应变软化U...利用声发射无损探伤技术实时监测三种类型超高性能混凝土(Ultra High Performance Concrete,简称UHPC)轴拉试验过程中内部损伤点的形成和演化过程,同时通过裂缝观测仪量测UHPC拉应变到达2000με时的缝宽。与低应变强化UHPC和应变软化UHPC相比,高应变强化UHPC具有高抗拉强度和"类金属"拉伸应变强化性能,在强化段区间内通过多点微裂纹均布开展的形式来平衡等量变形,表现出优异的裂缝宽度控制能力。气体渗透测试证明高应变强化UHPC抗气渗性能优异,且拉应变达到2000με后即刻卸载状态下的抗气渗性能仍要优于未受荷C50混凝土。基于高应变强化UHPC这些特性,将其应用于桥梁结构的高应力区或其他需要高抗裂性能的部位将是预应力混凝土之外的新方案,例如钢-UHPC轻型组合结构、斜拉桥的桥塔锚固区。展开更多
基金supported by the Team Interaction and Cooperation of the Science and Technology Program of the Chinese Academy of Sciencesthe Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX2-YW-JS402)+4 种基金the National Basic Research Program of China(2010CB732300)the Strategic Priority Research Program of the Chinese Academy of Science(XDB05050200)the National High Technology Research and Development Program of China(2012AA063101)the Program of Chinese Academy for Environmental Planning(2012A014)Beijing Municipal Natural Science Foundation(8112015)
文摘VOCs play an increasingly important role in affecting air quality and threatening human health in China in recent years,where industry activities show a significant contribution to VOCs emission.In this article we report our long term study of industrial VOCs emissions of six major industries (vehicle manufacturing,printing,equipment coating,electronic manufacturing,furniture manufacturing and bio-pharming) on the aspects of emission characteristics,environmental impact and health risk assessment,and control challenge analysis with the purpose to obtain in-depth understanding of industry VOCs emissions and offer some original basements for national control and management of industry VOCs emissions.This study shows that all these industries give middle or low emission with total VOCs concentration less than 1000 mg/m3 at each exhaust pipe.Benzenes,esters,alcohols,ketones,alkanes,chloroalkanes and alkenes were detected as the major emission components and the most frequently monitored VOCs were benzenes,which varied obviously with different processes and industries.The environmental impact assessments indicate that vehicle manufacturing and benzenes should be prior controlled with the purpose to reduce air pollution.While,health risk assessments suggest that furniture manufacturing and chloroalkanes should be firstly controlled.Control analysis indicates that developing technologies with low cost and high efficiency and establishing and completing specific industry emission standards/regulations are the two key issues in VOCs emission management at present stage.
文摘农业机械作为一种重要的非道路机械类型,其主要动力源为柴油机,而柴油机固有的燃烧方式会导致其颗粒物(PM)和氮氧化物(NOx)等污染物排放严重,开展农业机械污染排放控制技术的研究对人体健康和环境保护均具有重要意义。该文从农业机械排放法规、降低农业机械污染排放的单项技术路线、满足更高排放限值要求的组合技术路线3个方面进行阐述。农业机械排放法规分析了欧盟、美国和中国法规对排放限值和测试循环的要求以及各国法规的差异。中国目前正在实施的农业机械国III排放标准,与欧盟的Stage IV和美国Tier IV标准相比,排放限值相对宽松;欧盟农业机械排放法规的NRSC测试循环主要包括8工况循环和5工况循环,而中国和美国规定,19 k W以下的非恒定转速的农业机械柴油机也可使用6工况循环进行测试;欧盟和中国规定污染物测量的最终结果为冷启动循环结果的10%和热启动循环结果的90%的加权,而美国将冷启动循环结果的比例调低至5%。单项技术路线对油品技术、机内净化技术和机外排气后处理技术进行了介绍。其中,油品技术包括提升燃油和润滑油品质、采用替代燃料等;机内净化技术包括农业机械柴油机本体优化设计、增压及增压中冷、燃油喷射优化和废气再循环(exhaust gas recirculation,EGR)等;机外排气后处理技术包括柴油机氧化催化转化技术(diesel oxidation catalyst,DOC)、柴油机颗粒捕集技术(diesel particulate filter,DPF)和选择性催化还原技术(selective catalytic reduction,SCR)等。组合技术路线总结了满足国III和国IV阶段以及国外最新排放标准的技术路线。"优化燃烧+SCR"技术路线的柴油机比采用"EGR+DPF/CDPF"技术路线的柴油机节省5%~7%的油耗,若扣除尿素消耗,前者仍有一定节油优势;模块构建和单体式后处理系统等先进的农业机械污染排放控制技术是满足Stage I
文摘利用声发射无损探伤技术实时监测三种类型超高性能混凝土(Ultra High Performance Concrete,简称UHPC)轴拉试验过程中内部损伤点的形成和演化过程,同时通过裂缝观测仪量测UHPC拉应变到达2000με时的缝宽。与低应变强化UHPC和应变软化UHPC相比,高应变强化UHPC具有高抗拉强度和"类金属"拉伸应变强化性能,在强化段区间内通过多点微裂纹均布开展的形式来平衡等量变形,表现出优异的裂缝宽度控制能力。气体渗透测试证明高应变强化UHPC抗气渗性能优异,且拉应变达到2000με后即刻卸载状态下的抗气渗性能仍要优于未受荷C50混凝土。基于高应变强化UHPC这些特性,将其应用于桥梁结构的高应力区或其他需要高抗裂性能的部位将是预应力混凝土之外的新方案,例如钢-UHPC轻型组合结构、斜拉桥的桥塔锚固区。
